import "core-js/modules/es.error.cause.js";
function _defineProperty(e, r, t) { return (r = _toPropertyKey(r)) in e ? Object.defineProperty(e, r, { value: t, enumerable: !0, configurable: !0, writable: !0 }) : e[r] = t, e; }
function _toPropertyKey(t) { var i = _toPrimitive(t, "string"); return "symbol" == typeof i ? i : i + ""; }
function _toPrimitive(t, r) { if ("object" != typeof t || !t) return t; var e = t[Symbol.toPrimitive]; if (void 0 !== e) { var i = e.call(t, r || "default"); if ("object" != typeof i) return i; throw new TypeError("@@toPrimitive must return a primitive value."); } return ("string" === r ? String : Number)(t); }
/**
 * @typedef PageInfo
 * @property {number} startIndex The visual index of the first item in the page.
 * @property {number} endIndex The visual index of the last item in the page.
 * @property {number} pageSize The number of items in the page.
 */

/**
 * The module computes the state of pagination based on a fixed page size.
 *
 * @class FixedPageSizeStrategy
 * @private
 */
export class FixedPageSizeStrategy {
  constructor() {
    /**
     * The fixed page size.
     *
     * @type {number}
     */
    _defineProperty(this, "pageSize", 1);
    /**
     * Total number of items in the dataset.
     *
     * @type {number}
     */
    _defineProperty(this, "totalItems", 0);
    /**
     * Total number of pages.
     *
     * @type {number}
     */
    _defineProperty(this, "totalPages", 0);
  }
  /**
   * Calculates the state of pagination.
   *
   * @param {object} options Options for pagination calculation.
   * @param {number} options.pageSize The fixed number of items per page.
   * @param {number} options.totalItems The total number of items in the dataset.
   */
  calculate(_ref) {
    let {
      pageSize,
      totalItems
    } = _ref;
    this.pageSize = Math.max(pageSize, 1);
    this.totalItems = totalItems;
    this.totalPages = Math.max(1, Math.ceil(this.totalItems / this.pageSize));
  }

  /**
   * Gets the total number of pages.
   *
   * @returns {number} The total number of pages.
   */
  getTotalPages() {
    return this.totalPages;
  }

  /**
   * Gets the state of a specific page.
   *
   * @param {number} currentPage The current page number (1-based index).
   * @returns {PageInfo | undefined}
   */
  getState(currentPage) {
    currentPage -= 1;
    if (currentPage < 0 || currentPage >= this.getTotalPages()) {
      return;
    }
    const startIndex = currentPage * this.pageSize;
    const endIndex = Math.max(0, Math.min(startIndex + this.pageSize - 1, this.totalItems - 1));
    return {
      startIndex,
      endIndex,
      pageSize: this.pageSize
    };
  }
}